Fluid actuated mechanisms



April 4, 1961 BAINES FLUID ACTUATED MECHANISMS 2 Sheets-Sheet 1 FiledNov. 29, 1957 IMKA X W max In ewe! hm INVENTQR Leslie Baines RTTORNEYSApril 4, 1961 BAlNEs 2,978,044

FLUID ACTUATED MECHANISMS Filed Nov. 29, 1957 2 Sheets-Sheet 2 NVENTORLeslie Baines 122M aw W FLUID ACTUATED MECHANISMS Leslie Baines,Wakefield, England, assignor to Richard Sutcliife Limited, Wakefield,England, a British com- Filed Nov. 29, 1957, set. No, 699,633 7 Claimspriority, application Great Britain Nov. 30, 1956 4 Claims. (c1. 175-144This invention relates to fluid actuated mechanisms 1 for reciprocatinga member and has particular reference to mechanisms actuatedhydraulically. v 7 According to the present invention tiuid actuatedmechanism for reciprocating a member comprises a. double a actingcylinder, a piston reciprocable :within the cylinder, a power unithaving two pumping means for supplying fluid under pressure to thecylinder to produce reciprocation of the piston, and in which theoutputs of each of the pumping means is" greater than that which is'utiliz able by the cylinder, means being provided torreceiving'theexcess output.

In one embodiment of the invention, the pumping means operate inanti-phase and the excess output of one pumping means is receivable bythe other means.

In another form of the invention each pumping means is connected to anaccumulator which is loaded to receive from the pumping means only theexcess'outpu-t of the latter. l

Alternatively, the-means for receiving "excess output may comprise asource of low pressure fiuid to which the pumping means are connected.Flow of excess output to the source is controlled by valves which may besuitably loaded or may be mechanically operated to open at suitablemoments. 9 7

Alternatively, the cylinder may be formedwith ports which are uncoveredduring movement of the piston in the cylinder to permit excess output toflow to the source. The reciprocating movement of the piston istransmit- .ted to the niember 'or members tobe reciprocated. The member;may; consist of a shaft which passes longitudinallythrough the axis ofthe piston and whicli has a flange or collar. which, is struckperiodicallyby the'piston,,thi1s imparting; to the shaft a blowof apercussive H nature ff 5. Q The power 'unitmay' supplyfluidunderpressure to a i j: number of cylinders, each containing areciprocablepisgreater detail with eference. to thetaccompanying' drawlagrarnmaticform ig. Z' is aside inbodiment.

ws-a s'econd embodirnent in diagrammatic d -elevati on with halfsections on the ,jprises a pow'ei unitfwhi ch includes shaft lf carryingan eccentric 2,;foriimparting recip rocatory movement to pistions withrespect to-"shaft 1.,

By Way offexampleionly, hydraulically operatedrotary. foruse in coalmining equipment ntion will now be described inv first embo diment oftheinvention in 65 i Refemng to 1 flier-mechanism illustrated com- I i1stem i atented Apr. 4, 1961 The pistons 3, 4 are moveable in the housing5 against springs 6, 7 respectively. 1

The outputs of the hydraulic pumps are applied via pipe lines 8, 9 to adouble-acting cylinder 10 at opposite ends thereof. The cylinder has apiston 11 mounted upon a shaft 12 which is the shaft of a rotary pick ordrill. 1

The pipe lines 3, 9 are also connected to hydraulic accumulators 13 and14 respectively and also to inlets 15 and- 16 containing ball-valves 17,18 respectively. The inlets 15, 16 are both connected to a source of lowpres sure hydraulic liquid (not shown) so that any deficiency of liquidin the system, due to irregularities of liquid in the swept volume ofthe pumps and/or leakage, can be made up.

The hydraulic pumps are of a capacity such that they delivery to thecylinder 10 a volume of liquid slightly in excess'of the volume whichthe cylinder can accept, the excess volume being pumped into thehydraulic accumulators connected to the pumps.

Before use, the shaft 1'is coupled to a suitable source ot power whichmay be a hydraulic motor. After the system has been filledwith'hydraulic liquid, rotation of 'the eccentric 2 reciprocatesthepistons 3, 4 and liquid is pumped to and withdrawn from opposite ends ofthe cylinder 10 causing longitudinal movement of the shaft 12.

power unit the point at which overspilloccurs can be arranged so thatthe piston is travelling at maximum optimum speed after an accelerationperiod and is therefore able to give the maximum possible blow to thedrill. pistons 3, 4 are driven by an eccentric and so the speed of thepiston 11 will vary sinusoidally. In this case the For example, in theembodiments illustrated the sweptvolumes are arranged so that overspilloccurs immediately after the acceleration of the piston 11 passes itsmaximum value when .the piston has its optimum velocity.

The hydraulic accumulators 13, 14 are loaded so that only the excesshydraulic liquid passes into'them. Loading may be effected by means ofsprings or a gas or the accumulators may consist of an oil filled steeltube or rubber hose.

. FiguresZ and 3 of the accompanying drawings show the inventionembodied in a rotary percussive pick or drill suitable for use in coal:mining machines. In Figtu'es 2 and 3 parts identical with parts. shownin Figure l have been given the same-reference numbers.

.The'shaft 1 is driven by an hydraulic motor 19 having an inlet 2!} andan outlet 21. for the supply and exhaust of Working liquid and issecured to the housing 10 containing thesh'aft 12 of the drill. Apart ofthe eccen- Z is shown in Figure 2 and its eccentric'movement 3 istransmitted tothe pistons 3, by means of a ring 2,2

supported on the eccentric by'roller bearings 23; 'As

"can. be seen from Figure 2, the housing ltiis formed to accommodate thepistons 3, 4 and their springs 6,7. 'Thehousing also has an inletaperture 24 communicating withaninternal passage 25 connected topassageways 26 .and. 27 leadiugto each piston. Flow of liquid fromthe'passageways' 2 6, 27 is controlled by the nonreturnvalves 17.aridifirespectively 5 '1. v

' Movement of hydraulic liquid betweenzthe pumps, and

i ,7 v V q p q v V theinterioriof the hoiisingltitakesplace-viapipelines tons fi, of. twofhydraulie'pumps. .The'. pistons are mountedin afhousing Sin diametricallyropposedposi- 8 and ,9 which. are showndotted in; Figures 2 and 3.1 The pipelines communicate; with two narrowannular spaces .between the piston or fiiammer 11 andthe interior wall 3of the housing lltl. Leakage along the hammer 11 is prevented by thesealing blocks 28 fitted with piston-ring seals 29. The blocks 28 areheld in enlarged bores 30 in the housing 16 "by means of flanges 3i and'setscrews.

One end of the shaft 12 on which the piston 11 is slida'bly mounted isrotatably supported in the housing 10 by roller bearings 32 while theother end of the shaft is splined to pinion 33 supported by ballbearings 34 in the housing 10. The shaft 12 also has a portion 35 ofenlarged diameter, one end of which forms an anvil against which thehammer 11 operates.

The forward end of the shaft 12 projects from the housing 19 and isformed to receive a pick-head 36 secured to the shaft by a coupling 37.The forward end of the shaft also carries another coupling 38 whichpermits water to be pumped into the shaft end and through the pick-headto flush a bore-hole made by the pick-head.

The housing 10 also accommodates an air recuperator or shock absorberfor absorbing the impact of reverse movement i.e. movement to the rightas seen in Figure 2, of the hammer 11. The recuperator consists of apiston head 39 secured to the hammer and movable therewith in a chamber46 in the housing It The chamber 40 also accommodates a backstop 41which limits reverse movement of the hammer.

In addition to the reciprocating movement imparted to the shaft 12 byhammer 11 the shaft is also given a rotary motion. The pinion 33referred to above meshes with the second pinion not shown, which in turnengages pinion 42 secured to the shaft 43 of a hydraulic motor 44. Themotor 44 has an inlet port 45 and an outlet port 46 for the supply andexhaust of working liquid.

The hydraulic accumulators 13, 14 shown in Figure 1 are, in theembodiment shown in Figures 2 and 3 mounted on the housing It} and areconnected with the pistons 3 and 4 by means of pipelines 47 and 48respectively.

The inlets 20 and 45 of the two hydraulic motors are joined to separatesources (not shown) of pressurized hydraulic liquid and the inlet 25 isconnected to an external source of make-up liquid. The exhaust ports 21and 46 of the motors are joined to a suitable resorvoir tank.

Rotation of the shaft 1 by the motor 19 reciprocates the pistons 3 and 4and hydraulic liquid is pumped through the pipes 8 and 9 first to oneside of the hammer and then to the other, causing the latter toreciprocate rapidly on the shaft 12 and impart a series of hammer blowsto the anvil 35. At the same time motor 44 rotates the shaft 12 via thepinions 33 and 42..

Figure 4 of the accompanying drawings shows, in diagrammatic form only,a further embodiment of the invention in which excess working liquidcirculates between the pumping means. In Figure 4, parts identical withthose shown in Figures 1, 2 and 3 have received identical referencenumbers.

The mechanism shown in Figure 4 has a power unit which includes theshaft 1 which carries the eccentric 2, arranged to impart areciprocating movement to pistons 3 aud t against their respectivesprings '6 and 7. V

The pumping means are positioneddiametrically opposite to one anotherwith respect to the shaft and the eccentrics are arranged so that themovements of the pistons 3, 4 in their respective cylinders are-inanti-phase.

The outputs of the pumping means areapplied to the double-actingcylinder 19 at opposite ends thereof by means of suitable pipe lines 8and 9. The cylinder contains a piston 11 having tubular extensions 50and 51 and a central passageway through which passesthe shaft 12 of therotary percussive pick. The shaft 12 has a flange or collar 52 andpasses through a bearing indicated diagrammatically at53. A helicalspring 54-may be supused by the cylinder 16 and the excess is fed bymeans of a spring-loaded discharge valve 55 and a pipe line 56 into theline 9. Similarly, a spring-loaded discharge valve 57 and line 58 isprovided to enable excess output from piston 5 to be returned to line 8.

The lines 8 and 9 are joined via make-up valves 59 and 60 respectivelyand pipe line 61 to an external source of low pressure hydraulic liquid(not shown) so that any deficiency of liquid in the system due toirregularities in swept volume, leakage, and other causes can be madeup. A master pressure-relief valve 62 prevents an excess of liquid inthe system.

The operation of the embodiment shown in Figure 4 is similar to that ofthe embodiment described above.

Liquid pumped by the piston 3 to the cylinder 16 causes movement of thepiston 11 to the right as seen in the drawing against the action of thespring 54. Since the pistons 3 and 4 operate in anti-phase, piston 4 iswithdrawing liquid from the cylinder. After the cylinder 10 has absorbedits maximum volume of liquid excess passes to the line 9. The action ofpiston 4 is similar except that in this case movement of the piston 11occurs to the left and a blow is imparted to the flange or collar 52.

In another embodiment of the invention, valves control the flow ofexcess hydraulic liquid from the pumps and are mechanically controlledto open and close at required instants. The cylinder in which the pistonreciprocates may, alternatively, be formed with ports which are coveredand uncovered by the piston during its movement to control the flow ofexcess liquid.

It will be appreciated that the pumps may be driven by other forms ofmotor, for example electric or pneumatic motors, could be used and suchmotors are also suitable for rotating the pick or drill.

Iclaim:

1. A high speed percussive mechanism comprising a housing, a cylinderformed within the housing, hydraulic liquid contained in the cylinder, ashaft mounted coaxially with the cylinder and extending through one endthereof, an anvil face on the shaft, a double acting piston 'slidablymounted within the cylinder for reciprocation relative to said shaft, ahammer face on the piston for co-operation with said anvil face, adouble acting liquid transmitting power unit, a volume of hydraulicliquid contained in the power unit greater than the volume contained inthe cylinder, two outlets from the power unit, means connecting theoutlets to respective ends of the cylinder whereby transmission ofliquid through the connecting means by operation of the power unitrapidly reciprocates the piston relative to the shaft to causepercussive blows to be imparted to the shaft by co-operation of thehammer face and the anvil face during alternate strokes of the piston, adifferent hydraulic accumulator connected to each outlet, and loadingmeans for the accumulators, whereby only the excess hydraulic liquiddischarged from the power unit into .an outlet is absorbed by theassociated hydraulic accumulator, this excess hydraulic liquid beingreplaced byjthe same accumulator during subsequent discharge ofhydraulic liquid from the cylinder to that outlet.

2. A high speed percussive mechanism comprising a housing, a cylinderformed within the housing, hydraulic liquid contained in the cylinder, ashaft mounted coaxially with the cylinder andextending through one endthereof, an anvil face on the shaft, a double acting piston slidablymounted within the cylinder for reciprocation relative to. said shaft,'ahammer face on the piston for 'co-operation with said anvil face, adouble acting liquid transmitting power unit, two outlets ,from theported between the bearing 53 and one end of the tension 51 of thepiston 11.

The volume of hydraulic-liquid, for example a suitable I an,displaced'bypiston 3 is'in excess of that which can be power unit, meansconnecting the outlets to respective ends 'ofthe cylinder,hydrauli'cliquid contained in they power-unit, the volumeof liquidtransmittable from the power unit into an outlet'being in excess of thatreceivable by the portion of the cylinder to which that outiet isconnected, whereby transmission of liquidthrough the connecting means byoperation of the power unit rapidly reciprocates the piston relative tothe shaft to cause percussive blows to be imparted to the shaft byco-operation. of the hammer face and theanvil face during alternatestrokes of the piston, a two-way flow relief valve arrangement connectedbetween the outlets, whereby the excess hydraulic liquid discharged fromthe power unit into an outlet actuates the relief valve arrangement toallow flow of the excess liquid in one direction through the reliefvalve to the other outlet.

3. A high speed percussive mechanism comprising a housing, a cylinderformed within the housing, hydraulic liquid contained in the cylinder, ashaft located within the housing and extending through the cylinderco-axially therewith, means mounting the shaft allowing limited slidingmovement thereof, a collar rigidly secured to the shaft near one end ofthe cylinder, an anvil face on the collar, a double acting hollow pistonsurrounding the shaft, the piston being slidably mounted within thecylind'er for reciprocation relative to the shaft, a hammer face formedon one end of the piston for co-operation with said anvil face, a doubleacting liquid transmitting power unit, two outlets from the power unit,means connecting the outlets to respective ends of the cylinder,hydraulic liquid contained in the power unit, the volume of liquidtransmittable from the power unit into an outlet being in excess of thatreceivable by the portion of the cylinder to which that outlet isconnected, whereby transmission of liquid through the connecting meansby operation of the power unit rapidly reciprocates the piston relativeto the shaft to cause percussive blows to be imparted to the shaft byco-operation of the hammer face and the anvil face during alternatestrokes of the piston, a oneway relief valve connected between theoutlets to allow liquid flow in one direction only, a further one-wayrelief valve connected between the outlets to allow liquid flow only inan opposite direction, whereby the excess liquid discharged from thepower unit into an outlet actuates one of the relief valves to allowsaid excess liquid to flow to the other outlet.

4. A high speed percussive mechanism comprising a housing, a cylinderformed within the housing, hydraulic liquid contained in the cylinder, ashaft located within the housing and extending through the cylinderco-axially therewith, means mounting the shaft and allowing limitedaxial sliding movement thereof, a collar rigidly secured to the shaftadjacent one end of and exterior to the cylinder, an anvil face on thecollar formed on the face of the collar nearer to the cylinder, atdouble acting hollow piston co-axially mounted to surround the shaft,the piston being slidably mounted within the cylinder for reciprocationrelative to the shaft, a tubular extension piece secured to either endof the piston to surround the shaft, the extension pieces extendingthrough the ends of the cylinder, a hammer face formed on the free endof the extension piece nearest the collar for co-operation with saidanvil face, a double acting liquid transmitting, power unit, two outletsfrom the power unit, means connecting the outlets to respective ends ofthe cylinder, hydraulic liquid contained in the power unit, the volumeof liquid transmittable from the power unit into an outlet being inexcess of that receivable by the portion of the cylinder to which thatoutlet is connected, whereby transmission of liquid through theconnecting means by operation of the power unit rapidly reciprocates thepiston relative to the shaft to cause percussive blows to be imparted tothe shaft by co-operation of the hammer face and the anvil face duringalternate strokes of the piston, a different hydraulic accumulatorconnected to each outlet, and loading means for the accumulators,whereby only the excess hydraulic liquid discharged from the power unitinto an outlet is absorbed by the associated hydraulic accumulator, thisexcess hydraulic liquid being replaced by the same accumulator duringthe next ensuing discharge of hydraulic liquid from the cylinder to thatoutlet.

References Cited in the file of this patent UNITED STATES PATENTS956,044 Dalmas Apr. 26, 1910 1,326,245 Worthen Dec. 30, 1919 1,384,661Guiley July 12, 1921 1,477,684 Berner Dec. 18, 1923 1,744,885 Groene etal Jan. 28, 1930 1,806,136 Weiss May 19, 1931 1,956,989 Lapointe May 1,1934 2,189,013 Loweke Feb. 6, 1940 2,260,268 Warren et al Oct. 21, 19412,766,590 Erwin et al. Oct. 16, 1956 2,778,605 Hunn Jan. 22, 1957FOREIGN PATENTS 44,349 France Oct. 1, 1934 194,995 Germany Feb. 4, 1908

